Appliance for teaching arithmetical fractions.



F. J. COLEMAN! APPLIANCE FOR TEACHING ARITHMETICAL FRACTIONS.

APPLICATION FILED IULYIT. 191;.

1,174,689, Patented Mar. 7, 1916.

2 SHEETS$HEET 1.

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F. J. COLEMAN;

APPLIANCE FOR TEACHING ARITHMETICAL FRACTIONS.

APPLICATION FILED JULYH. 1915.

1,174,689. Patented Mar. 7,1916.

2 SHEETS-SHEET 2.

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atto'zn M FRANK J. COLEMAN, or new YORK, n. Y.

APPLIANCE FOR TEACHING ARITHMETICAL FRACTIONS.

Application filed July 17, 1915.

.of a fraction to the unit.

A further object of the invention is the provision of means for identifying and presenting so that they are naturally associated in the mind of the pupil the fractions which are reducible by a common number as will be hereinafter more fully explained.

Referring to the drawings: Figure 1 is a front elevation of my device. Fig.2 is a side view. Fig. 3 is a detail view showing the method of mounting the strips. Fig. 4 is a vertical section through one of the strips, and Fig. 5 is a sectional view of a modified form of strip, and facing and backin sheets.

lieferring now to the drawings, in which like characters refer to like parts the numeral 1 designates a rectangular frame comprising ends 2 and 2, sides 3 and 3 and a backing f of suitable material preferably wood. vertically alined card supporting wires 5 having one end screw threaded as at 6 and the other end bent at right angles as at 7 are fixedly mounted in the side members as by means of nuts 8 screwing on the threaded ends 6 thereof, the angled portions 7 b ing adapted to snugly fit within a perpendicularly disposed groove 9 formed in the side 3. Short wires 9' are .loosely coiled at one end around the wires 5 the free ends of which wires 9 extend in a radial direction from the wires 5 for a purpose hereinafter described.

Mounted in the side members 3 and 3 of the frame between each pair of card supporting wires 5 are a plurality of rods 10 identical in construction and method of mounting to the wires 5. These rods 10 are located slightly to the rear of and are therefore out of vertical alinement with the strip supporting wires that is, the rods and wires Specification of Letters Patent.

A series of horizontally disposed PatentedMar. "2, 1916.

Serial No. 40,507.

are placed in staggered-relation one to the other.

Pivotally disposed upon the wires 5 eccentrically with respect to both their vertical and longitudinal axes is a series of strips 11 the uppermost of which has printed on tne front and rear face thereof the word Unit to indicate that this is the standard from which the fractions are taken.

In order to clearly impress upon the mind of the user the relationship between various fractions, I have divided each of the succeeding strips into the number of portions representative of the denomination of the particular fraction which each indicates.

For instance, the second strip is divided into two equal portions, the third into three equal portions and so on through any number of fractions. Each of these portions has printed on its front and rear face the fractions which the portions denote.

As persons beginning the study of a subject are often greatly helped by object lessons or illustrations my invention is particularly advantageous, because, the divisibility of one fraction into another is clearly illustratedin a mechanical way. Using the strip divided into two equal portions each representing one half of the whole as an example, the portion ofthe strip representing divisors of one half, as one fourth, one eighth or one. sixteenth illustrate by their length with respect to the one half portions the number of times each will be contained therein. The portions of the strip indicating the fractions one sixteenth are one eighth of the length of the portions of the strip indicating the fraction one half, the one quarter are one half of the length of the half strips, the eighth strips are one half the length of the quarter strips etc. Those fractions not divisible into a particular fraction or series of fractions are made evident by the dissimilarity between their respective lengths.

By disposing my strips in the manner shown in the drawings, common divisors may be found with respect to a certain unit diagrammatically, or more specifically by comparing the length of a certain number of the fractions desired to be divided into a unit with the length of the unit itself. I have also found it expedient to use some means to designate a particular class of fractions, for instance, the face of strips 11 may be variously colored.

here it is desired to disregard the color scheme entirely it is merely necessary to swing the strips about the wire 5 as a pivot bringing the back of the strips to the front. It will of course be understood that the back of strips 11 are all of a color.

The strips 11 consist of rectangular pieces and sheet material such as cardboard or the like having longitudinal grooves or depressions 13 therein adapted to accommodate the wire 5 as best illustrated in Fig. at or the strips are made of two pieces adapted to lie one on each side of the wire (see Fig. 5). In order to secure the strips in pivotal position upon the wires 5 I provide facing sheets and backing sheets 12 and 15 respectively which are attached to the strips by means of suitable adhesive. It will be noticed that the wires 9 lie within short transverse grooves 16 formed in the face of the strips 11 and that the projecting ends 16 are adapted by virtue of the eccentric mounting of the strips to contact the rods 10 and thus limit the oscillatory movement of the strips when the latter are oscillated about the wires 5 to bring the back of the strips to the fore. By reason of the fact that the rods 10 are located rearwardly of the pivoted wires 5 a sufiicient distance to compensate for the thickness of the strips the latter will always be in vertical alinement with the next lowermost or uppermost strip.

By the above description it is thought that my invention 7967' 86 will be readily understood, the relationship of the various fractions is clearly brought out both by relative length as compared with a unit and like color. The student of fractions, thus, has the common divisor of a particular fraction illustrated to him forcibly by two improved and cooperative ways, namely, by the length and color of the respective fractions.

Having thus described my invention, what I claim is:

1. In a device of the character described a rectangular frame comprising side and end members, one of said side members having a perpendicularly disposed groove, a series of horizontally disposed vertically alined card supporting wires having angled ends fitting in said grooves and a series of horizontally disposed rods secured to said frame, short wires coiled about said card supporting wires having radially disposed free ends, a plurality of strips pivoted upon said strip supporting wires having longitudinal and transverse grooves therein adapted to receive said strip supporting wires and said short wires respectively, facing and backing strips securing said strips to said wires, and fractional portions indicating certain fractions illustrated upon said strips.

2. In a device of the character described a frame, a series of horizontally disposed card supporting wires and a series of horizontally disposed rods mounted in said frame, said rods being staggered with respect to said wires, strips, eccentrically mounted on said wires, having transverse grooves therein, short wires coiled about said card supporting wires and fitting in said grooves adapted to engage said rods to limit the pivotal movement of said strips, the location of said rods to the rear of said card supporting rods being such as to compensate for the thickness of the strips whereby said strips are maintained in vertical alinement with the next uppermost or lowermost strip.

In testimony whereof I afiix my signature in presence of two witnesses.

FRANK J. COLEMAN. Witnesses JOHN B. COLEMAN, FRANCIS J. NILAN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). C. 

